Use a 1 pixel, non anti-aliased brush or pencil, with spacing at the desired value. Spacing is somewhere in the brush/pencil's "brush options", the one that has all the other stuff like pressure tablet settings and roundness jitter etc. If you haven't moved anything around, it should be at the bottom of the top-of-the-screen menus, on the right; a large box menu will appear when you click the right ****.
Then with the tool configured as you want, click once at the beginning of the rivet line, push and hold Shift, and click a second time at the other end of the desired rivet line to link your first and second clicks.
